Road charging is an economic concept regarding the various direct charges applied for the use of roads, including those which may vary by time of day, by the specific road, or by the specific vehicle type, being used. Road charging has distinct objectives such as revenue generation, usually for road infrastructure financing, and congestion charging for demand management purposes.
US 2005251327 A1 describes a route calculating system which comprises a device for setting and displaying an optimum route taking road pricing into consideration when displaying the route.
In order to determine where a car is, a satellite navigation system may be used, e.g. the global positioning system (GPS) system or, when it becomes operational, Galileo, or any other positioning system. GPS uses a collection of orbital satellites that transmit signals that enable GPS receivers to determine their current location, the time, and their velocity (including direction).
Some position information receivers such as GPS receivers may provide the calculated navigation information using a standardized protocol such as e.g. the national marine electronics association, NMEA, 0183 protocol. NMEA 0183, or NMEA for short, is a standard for communication between marine electronics devices which uses ASCII strings to format the protocol messages.
Many GPS receiver devices sold on the market (handheld and otherwise) have an output interface (usually RS-232 or USB) that can produce NMEA data. Navigation software typically expects to be able to connect to a GPS receiver device that produces NMEA data to be able to perform the navigation and display the correct map, etc.